you must be careful never to allow doubt to paralyze you. always take the decisions you need to take, even if you're not sure you're doing the right thing. You'll never go wrong if, when you make a decision, you keep in mind an old German proverb: 'The devil is in the detail.' Remember that proverb and you'll always be able to turn a wrong decision into a right one.
The materialist is sure that history has been simply and solely a chain of causation, just as the [lunatic] is quite sure that he is simply and solely a chicken. Materialists and madmen never have doubts.
Reagan did not suffer from the dismal plague of doubts which has assailed so many politicians in our times and which has rendered them incapable of clear decisions.
Everyone who observes himself doubting observes a truth, and about that which he observes he is certain; therefore he is certain about a truth. Everyone therefore who doubts whether truth exists has in himself a truth on which not to doubt.... Hence one who can doubt at all ought not to doubt the existence of truth.
Given the millions of billions of Earth-like planets, life elsewhere in the Universe without a doubt, does exist. In the vastness of the Universe we are not alone.
I know that there are those who disagree with the overwhelming scientific evidence on climate change. But here's the thing -- even if you doubt the evidence, providing incentives for energy-efficien cy and clean energy are the right thing to do for our future -- because the nation that leads the clean energy economy will be the nation that leads the global economy. And America must be that nation.
The majority of mankind is lazyminded, incurious, absorbed in vanities, and tepid in emotion, and is therefore incapable of either much doubt or much faith.